Amr Refky

Prof. Amr Refky

Faculty of Engineering, Al-Azhar University, Cairo, Al Qāhirah, Egypt
orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 June 2022 in Journal of Electrical and Computer Engineering
Verified
Journal Article
Open access
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MSMohamed Ezzat Salem
Mohamed Ezzat Salem
HSHamdy Abd ElHalim Shatla
Hamdy Abd ElHalim Shatla
Amr RefkyAmr Refky
Amr Refky
INIbrahim Ahmed Nassar
Ibrahim Ahmed Nassar
This paper proposes a study on the potential of waste-to-energy (WTE) possibility in the Arab Republic of Egypt. WTE is a viable option for municipal solid waste (MSW) management and a renewable energy source. The issue of waste spread is a chronic environmental challenge in the Arab Republic of Egypt. The MSW practices in Egypt are simply done by collecting the waste and dumping it in open landfill sites. This research aims to assess the potential contribution of the WTE facility to meet electricity demand in Cairo City, which is Egypt's capital and the biggest city in population as a sample, and then apply the results to all of Egypt. The paper introduced a step-by-step calculation for the electrical power that can be generated from Cairo MSW. Four scenarios for WTE utilization were developed: Mass Burn without any waste processing, Mass Burn with 25% recycling, Mass Burn excluding 50% of organic material, and Mass Burn excluding 50% of organic material with 25% recycling. The Mass Burn scenario implies full MSW stream incineration; the Mass Burn with recycling scenario considers a partial separation of reusable materials and the waste leftover for incineration; the Mass Burn with excluding 50% of organic material scenario considers a partial separation of organic materials and the waste leftover for incineration; the Mass Burn with excluding 50% of organic material with 25% recycling scenario considers a partial separation of organic materials and partial separation of reusable materials and the waste leftover for incineration. The analyses were done for the period 2011-2031 for Cairo with a total population of about 10 million in Nov 2021. The results show the huge potential of WTE conversion as a source of renewable energy, which is a key factor in Egypt's sustainable development strategy 2030. Available data have been theoretically processed to show the decision-makers in Egypt the amount of electrical power that can be generated by using the WTE options to manage the MSW in Egypt.

31 March 2022 in Journal of Electrical and Computer Engineering
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Journal Article
Open access
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SESally Eltwab
Sally Eltwab
HMHassan S. Mohamed
Hassan S. Mohamed
Amr RefkyAmr Refky
Amr Refky
AAA. M. Abdel-Aziz
A. M. Abdel-Aziz
The power system self-healing concept needs accurate and reliable fault detection, classification, and location (FDCL). This research proposes a novel and robust FDCL approach for distribution networks (DNs) in proportion to self-healing requirements. The proposed algorithm utilized a discrete wavelet transform (DWT) to decompose the measured current and zero sequence current component of only one terminal (substation) to detect and classify all fault types with the identification of the faulted phase (s). The fault location is achieved by integrating DWT and support vector machine (SVM). The data for training were extracted using DWT and collected, and then SVM was trained to locate the faulted section. The simplicity of the applied approach, ignoring DG’s data that is merged into the system, reduced training data and time, ability to diagnose all fault types, and high accuracy are the most significant contributions. The proposed techniques are tested on IEEE 33 bus DN with two distributed generation (DG) units, which are simulated in MATLAB. The simulation results demonstrate that the proposed methods give more accurate and reliable results for diagnosing the faults (FDCL) of various fault sorts, DN size, and resistance levels.

25 March 2024 in Scientific Reports
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ANAbdelrahman M. Nasser
Abdelrahman M. Nasser
Amr RefkyAmr Refky
Amr Refky
HSHamdy Shatla
Hamdy Shatla
AAAlaa M. Abdel-Hamed
Alaa M. Abdel-Hamed
The Multilevel inverter (MLI) plays a pivotal role in Renewable Energy (RE) systems by offering a cost-effective and highly efficient solution for converting DC from Photovoltaic (PV) sources into AC at high voltages. In addition, an innovative technology holds immense significance as it not only enables the seamless integration of PV systems into the grid but also ensures optimal power generation, thereby contributing to the widespread adoption of RE and fostering a sustainable future. This paper presents a modified sinusoidal pulse width modulation (SPWM) control scheme for a three-phase half-bridge cascaded MLI-powered PV sources. The selection of the MLI configuration is motivated by its reduced number of switching components, which enhances system reliability and simplifies experimental implementation. Compared to the SPWM schemes which require (m−1) carriers that make the generation of the pulse circuit very complex, the proposed control scheme requires only three signals: a carrier signal, a triangular waveform, and a modulating signal. This approach significantly reduces the complexity of control and facilitates practical implementation. The proposed control scheme simulation is verified using MATLAB/SIMULINK Software. The grey wolf optimization (GWO) algorithm is implemented to determine the optimal switching angles of the proposed control scheme. The Total Harmonic Distortion (THD) objective is selected to be the fitness function to be minimized for improving the quality of the output waveforms. For verification, the results of the proposed GWO-based modified SPWM control scheme are compared with those obtained using both the Particle swarm Optimization (PSO) and Genetic algorithm (GA) used in the literature. Simulation results declared that the proposed control scheme improves performance, especially THD which is minimized to 6.8%. Experimental validation has been conducted by building a laboratory prototype of the proposed system. The experimental and simulation results gave acceptable and limited convergent results considering the experimental difficulties.

19 May 2022 in Journal of Engineering
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Journal Article
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HSHamdy Abd ElHalim Shatla
Hamdy Abd ElHalim Shatla
ESEl Sayed Soliman
El Sayed Soliman
Amr RefkyAmr Refky
Amr Refky
In this paper, the operation and a complete design of the bootstrap circuit elements when firing a high-side MOSFET feeding an inductive load are introduced. The operation for both low-side and high-side cases are discussed with complete design and analysis of the bootstrap circuit elements. The effect of the bootstrap capacitor (BSC), diode, and resistance on the MOSFET switch for inductive loads at different frequencies and duty cycles including regular and SPWM are briefly analyzed. The current discontinuity is associated with higher losses, discontinued power output operation, and derated performance. The precise good design of the bootstrap circuit elements enables to improve the load current continuity in a specified frequency range of operation preventing the demerits of discontinuous operation. The effect of high-side implementation on extra harmonic content on the load is discussed including THD measurement of both applied voltages and currents.

1 March 2022 in International Journal of Power Electronics and Drive Systems (IJPEDS)
Verified
Journal Article
Open access
ESEl Sayed Soliman
El Sayed Soliman
HEHamdy Abd El-Halim
Hamdy Abd El-Halim
Amr RefkyAmr Refky
Amr Refky
The higher solar energy urges to maximize the solar energy extraction and utilization. This paper aim is to propose a new technique for extending the daily extraction time via a proposed aggregated PV cell. This system idea is using group of the photovoltaic (PV) cells to behave as an interactive regulated cell according to the series or parallel connections, it can call it an aggregated cell. This can be realized by interactive switching system according to the single cell output voltage. Six 6V PV cells are used for configuring the proposed single aggregated 6V PV cell. The technique depends on both single-cell number and their interconnections pattern. Switching the panel connection between the fully series cells to full parallel ones according to either sunlight states or the single-cell output is automatically achieved using an interactive control system. This system includes a voltage sensor that implements the suitable switching pattern for the aggregated cell. The ripple voltages during both morning and afternoon low sun times, as well as due to any other reason such as the lower clouds are efficiently eliminated. The simulated and the experimental results show in a satisfactory agreement the proposed aggregated PV cell validation.

16 August 2024
Verified
Book Chapter
Closed access
MSMohamed Ezzat Elkotb Salem
Mohamed Ezzat Elkotb Salem
Amr RefkyAmr Refky
Amr Refky
INIbrahim Nassar
Ibrahim Nassar